Drawbench arm mechanism



Aug. 5, 1952 w. E. KERR DRAW BENCH ARM MECHANISM 4 Sheets-Sheet 1 Filed Sept. 12, 1945 m mm W R mm N H m w 2 mm Em m m W a. M M R 11 14%11 w 9 m E Y//// W QT? mi Q g 8 x B Q C Aug. 5, 1952 w. E. KERR DRAW BENCH AR M MECHANISM Filed Sept. 12, 1945 4 Sheets-Sheet 2 Wallace 5. Kerr.

Aug. 5, 1952 w, E, K 2,605,890

DRAW BENCH ARM MECHANISM 4 Sheet S Sheet 5 Filed Sept. 12. 1945 INVENTOR. Wallace Ker/1 Aug.- 5, 1952 w, E, E 2,605,85E6

DRAW BENCH ARM MECHANISM Filed Sept 12, 1945 4 Sheets-Sheet 4 FIBU ll a/kwe 5 Kerr.

Patented Aug. 5, 1952 UNITED STATE s PATENT oFFicE I DRAWBENCHABM MECHANISMQ Wallace E. Kerr, Youngstown, Ohio Y Application September 12, 1945,Serial No. 615,831 Q '1 Claims. (01.205-22) I c .1 This invention relates to metal drawing equipment and more particularly to improved stock discharging arm mechanisms for drawbenches. In metal drawing apparatus employing a die and a bench extending outwardly therefrom as ,wellas a grip carriage supported on the bench ithas been heretofore proposed to provide horizontally swinging arms s'paced'outwardly along the bench and to swing these arms in succession under the stock piece being drawn as the grip carriage. moves outwardly... In certain of these systems means is provided to rock the extended arms upwardly after the stockpiece is free of the die and carriage thereby ejecting the drawn stock piece from the bench. In other systems the arms are retracted horizontally and upstanding knobs on the free ends of the arms engage and move the stock piece off of the bench orgin the case of round stock, the arms may be sloped and be 'retracted'by swinging horizontally only after the stock piece has rolled off. v

Regardless of the specific natureof the-discharge arm mechanism as heretofore employed the ,arms were so positioned that. in swinging to extended positions they would pass under a stock piece of the maximum dimension which the machine was capable of handling. 7 Now if smaller sections were being drawn the stock piece would sag down behind the grip. carriage with a tendency of the gripped end to wedge in the grips. Upon the stock piece moving clear of the die and the consequent opening of the grips the stock piece would not always be freed from the grips, and would then have to be removed by hand. The present invention overcomes this difliculty'by snugly supporting the stock'pie'ce immediately prior to and during completion of the draw so as to avoid the above describedcanting and stocking of the stock piece in the grippers.- v i A further object of the invention is to provide an arrangement for further facilitating the disengagement of the grip carriage from the stock piece at the completion of a draw and this is accomplished by restraining forward movement ofthe stock piece after completion of the draw. Another object of the invention is to provide a drawbench discharge arm mechanism of the upward tilting type with resilient means to resist abrupt downward movement of the arm. Thus the arm mechanism is protected against severe impacts which sometime occur when the stock .pieces jump free of the die. I Yet another object of the invention is to pro- ;vide a drawbench discharge arm mechanism of the upward-tilting type means to tilt the arms slightly to snugly support the stock piece at the completion of a draw and adjustable means on the arms forming horizontal supporting surfaces for different sizes of stock pieces. By supporting the stock pieces on horizontal surfaces at the time of the completion of the draws the tendency of the stock pieces to cant or twist sideways is minimized and their disengagement from the grip carriage is thus facilitated.

Other objects of the invention include the provision of improved operating or driving arrangements for drawbench discharge arms of the horizontal swinging and upward tilting type and of an improved release mechanism for the latched arms. Further objects and advantages of the invention will become apparent upon consideration of the following detailed specification and. accompanying drawing wherein there is disclosed a preferred embodiment of the invention.

In the drawing:

Figures 1 and 2 are plan and side views, respectively, of a drawbench discharge: arm mechanism constructed in accordance with the principles of the invention:

Figures 3 and along the lines Figure 2; V y

Figures 5 and .6 are; plan views of the arm latching arrangements utilized in the assembly of Figures 1 and 2; i

Figures 7 and 8 are plan views illustrating the two limitingpositions of the armoperating crank and cylinder assembly utilized in the machine of Figures 1 and 2; i 5

Figure 9 is a fragmentary section illustrating a part of the rock shaft limitswitch operator;

Figure 10 is a schematic diagram of a control system which may be advantageously employed in connection withthe machine of Figures 1 and :2; and a Figure 10a is an limit switch. 3 2 Referring to the drawing, reference numeral l0 designates a die block or stand in which is positioned the die through which the stock is to be drawn. Extending outwardly beyond the die block I0 is a bench ll along which travels a carriage l2 mounting a pair of stock'grippers l3. In accordance with usual practice, means such as a chin, not shown, is employed to move the carriage outwardlyin drawing direction and other means as a cable, not shown, may be employed to return the carriage i 2 to the die ,blocklo. v

4 are .transverse sections taken 3-3 and 4-4, respectively, of

elevation of the rock-shaft prises a housing [6, which is rigidly clamped to the shaft l5 by means of the clamp bolts 17, for example. Journaled in the housing leis a pin #8 to the upper end of which is keyed an arm l9 and to the lower end of which is keyed a crank 23. Pivotally supported from an integral exten sion 2| of the housing I6 is a simplehydrauliecylinder 22 containing a piston theconnecting rod of which is coupled with the crank 20. "Extending outwardly from a boss also 'rormea'm-i tegral with housing [6 is a rod 23 to the outer free end of which is attached on end of a coil spring 24. The opposite end of, spring24 is connected with the, outer free end ofa crank" arm 25 whichis rigidlyconnefited with .the lower end of thepin ofthe'crank 20.1 Formedrasan integral partof the. arm .l9 or independently. keyed to the pin [8 is'alatchring, two types of which are utilized in the illustrated embodiment of the complete. system.' The. first of theserings, indicated by the reference numeral26.,,, is-.shown.in detail in Figure 5 and is utilized in the discharge arm assembly which isclo'sest .to the die block 53. As shown, latch 26 has,a segmental detent Elsubstantially'; aligned with the. longitudinal axis of arm-lEiand a second ratchet'detent 28 positioned on the outward side of the arm I?) when the arrn is in extended position. Each of the other arm-assemblies has a latch ring 29 which is'identical with the latch 26 except in the omission of; the second detent 28.-

Latches 26' and 291 are arranged; to be opera;- tively engaged by the dogs 30, on e;of which is pivotally mountedoneach-v ofthe-housings IS in position to be tripped bye-gate, type of -0perator3l mounted on the carriage; l2. Spring means, not shown, is employed tozbiasthe'dogs 30- into engagement with .the latches 26 ;and 29 as shown in Figures 1, Band 6. Figures 5 and 6 show the arms in extended position, of. course, so that if the arms are; now rotated proximately 90 in a-counter-clockwise direction to retracted positions the dogs 30 will engagethegshoulders of detents 26 to retain thearms. insuchxpositions. Suchretraction is accomplished-by the cylinders 22 and Figure 7 shows relative. position of one of the cranks 20 when thearmassociated therewith is in extended position. Figure 8 shows the relative position of the partstwhen the arm isretracted. I

The means employed to rockthe shaft I 5 comprises a cylinder 32 which ispivotally mounted at 33 on a bracket 34 secured to and extending downwardly and outwardly from the bench ll. Bracket 34 extends on the opposite-side of the bench II from the'shaft l5.- Cylinder 32 is of the double acting type andhas its piston rod connected with the crosshead 34". Extending through spaced apertures in 'crosshead 34"and through aperturesformed in the outer end of pins 35 isa pair of pull rods 36-.- The right ends of pull rods 36 are connected'with a pivot pin 3'? which passes through the lower end of a lever 38 which is rigidly keyed to the shaft I5. The ends of the rods 36 which pass throughthe crosshead 34' have retaining nuts 39 and coil springs 40 interposed between the nuts 39 and the mem- 4 ber 34. There is thus provided a yieldable driving connection, the purpose of which will be explained in detail below.

I provide a source of hydraulic fluid pressure comprising a conduit 4| which leads to four-way valve 42 which controls the operation of cylinder 32 and also to a three-way valve 43. which controls the flow of fluid into and out of cylinders 22. As shown in Figures 1,. and 10, valve 42 is provided with ports whichxare connected with opposite ends of cylinder 32 while valve 43 has ai port which is connected with a supply line 44 leading to all the cylinders 22. Valves 42 and 43 haveexhaust ports comiected with a fluid return conduit Valve 42 is of the self-centering type and when centered all the ports are blocked. The

. coretis-moved in one direction by a solenoid 42U andwhen this solenoid is energized fluid pressure is admitted to the inner end of cylinder 32 to, rotate the shaft I5 in the direction tending to rock thearms I9; upwardly (assuming these arms to'be; in extended positions).' A second solenoid 42D operates-the-core ofvalve 42-and is operative when energizedjtoactuate valve 42 in such manner that fiuid' is admitted to-the outer end of cylinder 32-to rock shaft t5 inthe opposite direction. It should be rememb'eredthat at any time when both solenoids- 42U'- and Bare deenergized the piston in oylinder 32- will be locked in the particularposition it has assumed at l that time. Valve 43 is' operated by a solenoid- 43R and 1 upon energization connects "conduits 4i and 44 while. blocking the exhaust port. c When the solenoidfiSRis de-energized.conduit is con"- nected with the'returniline 45 and the'supply ports of the valve 43are blocked; v

I provide a'noveLsystem for controlling the mechanism described above in a highly advantageous manner, and such control system may comprise relays R l R2 R3,' EandBA as well as, various limit. switches. 'operatedfimresponse to themtated. positioniof th'e shaft 1' l5. and in' response topositions of thegrip carri'age I2, Vand various manual control sw tches to; be hereinafter described -.in,.'Tdet'ail...-. As.;to.;the..carriag,e. operated switches, normally lclosed,.switch' 461s. positioned adjacent the die. head 'lllla'ndis arranged to .be opened when the carriage is. adjacent-toth'e. die head; Next outwardly alo'n'gthebench -.is..a nor 'mal ly'closed limits-Witch .41 the primaryiunction of which is to slow down :the return movement of thegripcarriage (not a feature of the present invention); Mounted- "atian' adjustable position furtherroutwardly-along the bench is-athird normally opened limit switeh48-the function of which- -is:;to eiiect slight initia} rotation of the shaft I5rin the direction necessary to "bringthe arms I9 up against the stock piecebeing drawn for the purpose initially explained; The'fourth limitiswitch .49; WhiChi may" comprise :awpair. of switches 'inseries; is: associated -with:,oneor: two of the. discharge arms and ---is1;arranged-to be closed whenthis' arm.:;(or.;'arms): is :infretracted, latched position:

The i. controlling limit switches; which: an: 'op era tive in response *to 3 the rotated position"v of shaft I 5 are the normally open switch'es 82 and S3 7 andthe 'normallyclosed 'swit'ches' S4 andfS I. These four switches" are adj ustably- (circumferentially) mounted in a drum 50 secured to the side of bench H opposite-shaft '15. Thesefour switches are arranged to--be operated by adiametrically opposedpair of spokes 5t and 52 *pro- -jecting'outward'ly from-a hub '53 keyed to ashaft piece being I '(opened) to de-energize solenoid 42U whereupon 2&95899 54. S haft ;54 is-arranged to be rotated inproporon t air iai s s a t. '5 b means 9 gears 55. which effect multiplication of heme;- tion of the shaft I5. As'viewedinEigure 1o, shaft 54 rotates clock-wise as shaft I rocks to move a ms,.- f PW -j '1 '1 1A anu alfswitch 56' having normally "closed contacts 51 and'norm'allyopen contacts 56 is provided to effect frock-up o'tflthe arms I9 under manual control while a manua switch 59 having normally closed contacts" '69 and' normally ope nconta'cts BI is provided to effect retraction of the arms launder manual control. Normally the grip carriage 'r'eturn motor, not ehown,is "energized automatically 1 (upon actuation of a switch 49) but under certain circum'- stances it may be'desirable to efiect 'energ'izatio'n under; manual control andior" this purpose I provide a f normally open. manually controlled switch' 62. "A manualswitch 6371s in'parallel with limit switch'fiil. j J 1 At the start of a draw the arms I9 are latched parallel with the bench and as evident from'Fig ures 112 and '8 the springs 24 are tensioned tending to swing the arms across the bench. As the carriage I2 passes each arm assembly the op.- erator 3I trips the dogs 30 allowing the arms to swing to transverse positions in back of the ,carriageand the arms are maintained in such positions by reason of the orank arrangement (2 5) as will be understood. The fdet'ent28 in the latch of the first arm prevents this firstarm from swinging beyond" transverse" position whilethe succeeding arms are freeto swing in either direction from transverse or extended positions. As the draw approaches completion limit switch 48 is closed by-the carriage to energize relay RI througha circuit-line conductor LI, contacts 51, conductors 65 and 66, contacts 69, conductors 61 and 68, switch 48-, conductors 69 and I5, contactor IR4 of relay R3; conductor I9, coritactor IR2v of relay R2, conductor I I, relay coil RI, and conductors I2 and E3 to line conductor L2. Y A holding circuit for relay RI is provided through conductor '61, conductor 14, contactor IRI ofrelay'RiI, conductors i6 and I5, contactor IRA, conductor I9, contactor IR2 and conductor II. 7 At this time solenoidliZU isenergized through the circuitconductor LI, contacts 51, conductors 65 and 66, contacts 66, conductors 61, I4 and 14, contactor IRI, conductor I6, limit switch S4, conductors Hand I8, solenoid 42U, and conductor 19 to line iconductor L2.' Fluid is now admitted to inner end of cylinder 32 and when the shaft I5 is rocked sufficiently to bring the upper surfaces of the arms I9 almost into engagement with the stock drawn limit switch S4 is actuated the piston in cylinder 32 is locked injits current position. Now as the stock piece leaves the die the. same will be supported indirect alignment with the grippers on carriage I2 so that upon opening of these grippers the same maybe moved freely away from'the end of the stockpiece.

Such disengagement is'ab'etted bythe locking of the first arm '(dete'nt 28) against swinging movement in the direction following the movement of the carriage. f Y

Upon the stock piece being free of the die and carriage the operator may eject the piece from i the machine by depressing switch 56 which establishes the circuit-conductor LI, contacts 58,

conductors 89 and 1-8, solenoid 42U, and conductor 19 to line conductor L2 The arms I9 now 'tilt "upwardly and the" position response operator ifi l closes switch S3 to energize relay R2 through the circuit conductorslli I, and SI ,switch'S3, conductor 82, the coil o'f relay R2, and conductors and I3 to line conductor L2. I A holding circuit for relay IR: is. established through" nae. conductor Ifcondukztor 84, switch 41; 1cdr'1jauctor1s5, cone tact'orf2R2Iof relay R2, c0nductors'86andQ82, c ilof rlayRZ, and'ic'onductors 8'3 and I3 to line conductor L2.' "Relay R12 has a third contactor 3R2 so that upon'the ejecting'of the stock piece, and the-release of switch 56 solenoid 42U willbeTde-energized (opening of contact 58) and solenoid I421) energized, the latter through the circuit-conductor LI, contacts 51, conductors 65, 61,88, a co'ntactor'2RI of relay RI, conductor 89, cdntactor 3R2, conductor limit switch "SI, conductor v I conductor L2. 1 Whil lthe armada move totheir positions switch S2 is closed 'to energize relay R3 tlirough the circuit. conductor LI; con 'tacts5'I, conductors 65, 81, .88, contactor .2RI, conductor .89,""conta'ctor 3R2, conductor 90, switchS2, conductor'92, coil of relay R3, and conductor 93' to conductor I2; A holding circuit for relay'RS is established through conductors LI and.84,' switch 41,v conductor 85, contactor 2R2, conductors 86.9116. 94, contacto'r, IE3, conductor 95, coil of relaylR3',land conductor 93 to conductor L2. When the arms'freaoh' non-tilted positions switchsl opens tone-energize solenoid T" l Relay R3 is provided with a sc'ondjcontactor 2R3 which energizes solenoid 143R through circult-conductor LI, contactor' 51, conductors 65, 6 1, and 95, contactor 2R3, conductors 96 and I03, solenoid 43R, and conductors 91' and I9 to conductor L2. This admits fluid 'pressure'to cylinders 22 and the arms are retracted and latched in positions parallel with the bench. Upon. this "being accomplished the carriage may bereturned a'ndjfor automatic ,opera'tion i provide relay R3 with the'third contacto'rl 3R3. which energizes'relay R4 through the circuitconductor LI, switch '49, conductor 91, 'coiitactbrl3R3, conductors 98 and 99', coil' of 're1ay R4, and conductors ,I 09' and 113'tofconductor L2." Relay' R lfhas aconta'ctor 2R4 whichfupon closing, energizes'the carriage return moto'r, not shown. A holding .circuit'is provided for relay R14 consisting of conductor Ll conductor IIIjI, switch flB, conductor I02,"contactor 3R4, conductor 99; the coil of relay R4, and conductors I09 and I3 to conductors L2.

As the carriage returns switch 41 is'engaged andopened thus deenergizing relay R2 and relay R3','switchf4 1, being in the holdingbircuits for these relays. Relay RI is ,de-energized at the time relay R2 is initially energized and so all the solenoids are de-energized. Carriage I2 continues towardthe dieblo'ck and opening of switch 46 "de'-energizes relay R4 thus restoring the system' to its initial stateipr'eparatory as "its next succeeding cycleofoperation. j The arm I9 may be retracted at anytime underfmanual .control by. depressing switch 59 which energizes the, solenoid '43Rthrough the "circuit-conductor L rb ntacts 5'I,v conductors 65 and, 66, contacts '6I',"conductor I03, solenoid 43R, andfconductors '91 and I9 to conductor L2. The armsmaybe tiltedkupwardly a slight distance by depressing switch '63, the energizing cir- 9I, solenoid 42D, and conductorll9 to attests establishes the circuit conductors" LI, 104,.

switchBZ;andconductors H15 and 99 to coil of relayofR lz" f I b we 7 V b To provide the-generally horizontal surfaces for supporting the'stock pieces immediately upon their disengagement ir-om the die and; grip; I detachably momrtja': block It" on each of the arms l9 (Figure 3); The blocks; I01 are secured to the top surfaces of" arms l9 by the equidistant capiscrews l flt andeach of the blocks 10'! is provided with the three I inclined surfaces I09, H; Ill. diameter .or transverse dimension the' surface Hll willi en'gage"the" stock and sincethis surface m'akes but a small angle with thetopsurface ofthe arm proper the' arm need tilt'but a small amount tobringsurface HO to horizontal position; Thislarge stock does not, of course, requiremuch tiltingi movement of thearlns to bringthem' into engagement with the stock. For smaller size stockthearms must tilt up further and this extraangularity is compensated for by the greater slope of surface I09 which then engages the stock. By pivoting block I01 about the center cap screw the third surface HI may be employed for a stillsmaller size of stock and if desired this third surface may be slightly concaved as showninFigureB. o

' I It shouldbeobserved'that upon retractionof the arms from upwardly tilted and'extended positions (immediately after ejectment of a stock piece) by the cylinders 22the arms will swing through downwardly inclined" arcs and the weight of the arms will therefore exert a progressively increasing torque in a downward direction. This torque augments the forces exerted by cylinders 22', which aid is particularly advantageous as the efiiciency'of the cylinders 22 diminishes. toward the ends of their strokes. Compare Figures '2 and. 8. Thisinc'reasing torque also counteracts the increasing opposing forces exerted by the expanding springs 24 1 During normal retraction of the arms both the solenoids 42D and 43R arev energized so that the tilting cylinder 32' and. swinging cylinder 22 are simultaneously supplied with fluid from a common'source'. 'By'referring to Figure 3 it willbe noted that the arm. assemblies are over-balanced in an outward direction, particularly when the arms I9 are extended and tilted upwardly and so appreciablepressure'is required to tilt the arm downwardly. Lesspressure is required to retract the arms (by cylinders 22) and consequently the fluid will first flow into the cylinders 22 to complete the retraction of the arms in the manner described in the paragraph immediately above before suificient pressure is built up in cylinder 32' to rock the shaft l5'and bring the housing I 6 into their initial vertically aligned positions.

, While normally it is desirable to delay the. release of the'arms su fficiently to enable'the grip carriage to move some distance past theextended position ofthefpai'ticular arm to avoid excessive impact of the arid against, thefca'rriage, it may be desirable to prematurely release that'arm which is closest tothe stock point".when. the stock piece leavesthe die" so. that the released swinging arm follows directly in back of the Lc'arriage'. 'Ilhis Thus for} stock of large desist setriat it may e readily applied to any maybe accomplishedb'y providing theldog. (30') r of the last arm'assembly used with a vertical extension I I2 (Figures '2 and 4'); which is engaged and operated" only by a gate type of operator 1 l3 which is positioned on the earriagef l2 higher and moretothe-front th air the operator 3i. The T5 extension of 'l 2 isreadily detachable from the providedon the relay 32 should therefore be had to the of-the arinmechanisms. This feature is of advantage particularlyin the case of short or limber stock as will be understood.

The operation of the above described apparatus should be readily apparent, if it is remembered that the operation of the discharge arm system is entirely automatic (normally) except for actual dischargeof the 'stock by manually depressingswitch fi fi. At the start of the draw the arms are in retracted horizotal positions parallel withthe bench; and as'the grip carriage moves pastthe respective arms" the arms are released and extended across the bench under the stock piece being-fdrawn; Near the completion of the draw the carriagecloses switch 48 which energizesrelay RI, the contactor IRI of which energize'ssolenoi'd '4 2U through limitswitch S4. The position of the latter is adjustable, of course, so that upon the arms contacting the work piece rotation of shaft I5 is halted and locked (by the fluid in cylinder 32 and valve 42). When the operator observes that the stock piece is clear o f thedie and grip carriage he may depress switchfiti to energize'solenoid 42U irrespective of the open switch S4 andthrough switch S3 relay R2 is energized-when the arms reach their upper positions andthe stoolr'piece is ejected. Closing of relay R2- de' energizes relay RI and soleturns to the die block until opening of switch 46 de-energizes relay Rdto stop its further movem t-i,

Ifj deSl Ted,"thlll'ilit switch S2 as well as the relay 33 may beeliminated from the control circuit-described above and additional contactors so that immediately uponthe armsattaining their upper tilted positions'and the subsequent release of switch 56 both the-solenoids 43R and42D will be simultaneously energized. j Irithis alternate method of control thearm'syof. course, will first be retracted before the'shaft lt retracts to bring the arms to horizontal positions for' reasons pointed out above. Also; if desiredswitch 49 may be located in other relations to: thedischarge arm mechanism that it'clos'ed only when the arms are in retracted.

latohed 'positions. Thus the grip carriage cannot beginits' return movement until the arms are retracted and latched.

The above specifically described embodiment of; the invention should be considered as illustrative'only since obviously many changes may be madefltherein' without departing from the spirit V or scope of the invention. Reference appending claims indeterm'ningthe scope of the invention.

What Iclaim is? 1. A metal drawing-apparatus having a grip carriage and a discharge arm adapted to be moved to operative position below the stock piece being drawn andfmountedfor upward tilting movement to support the stock piece in approx- :in ate alignment with the grip onsaid carriage, means'for effecting said upward I tilting movement .of sai'd 'arm 'andadjustablemeans for limiting the extentofsaid'upward tiltingmo'vement, said arm having an angularly disposed upper plane surface which will assume substantially a horizontal position when the arm is tilted upwardly to engage said stock piece.

2. In metal drawing apparatus having a discharge arm adapted to assume an operative position below a stock piece being drawn and being mounted for upward tilting movement, means for effecting said upward tilting movement of said arm, and adjustable means for limiting the extent of said upward tilting movement, said discharge arm having a separable member on its upper surface mounted for end-fcr-end interchangement on said arm, said separable member having diiferent ang larly related supporting surfaces ad acent its ends.

3. In meal drawing apparatus having a die, a grip carriage movable away from said die, discharge arms mounted for movement from positions outside the path of travel of said carriage to positions below the stock piece being drawn and intermediate the die and grip carriage, and means for moving said discharge arms in an upward direction when in said operative positions;

the combination with said arms of operating means to move said arms upwardly, and means operative upon said arms reaching upper positions immediately below the stock piece being drawn to interrupt actuation of said operating means whereby the horizontal position and alignment of said stock piece is maintained during the disengagement of said stock piece from said die and carriage.

4. The combination of claim 3 further including means to re-initiate actuation of said operat-- ing means for effecting further upward movement of said arms to eject the stock piece from said apparatus.

5. In metal drawing apparatus having a die, a grip carriage movable away from said die, discharge arms mounted for movement from positions outside the path of travel of said carriage to positions below the stock piece being drawn and intermediate the die and grip carriage, and means for moving said discharge arms in an upward direction when in said operative positions; the combination with said arms of operating means to move said arms upwardly, means to initiate actuation of said operating means upon said carriage reaching a predetermined position outwardly of said die during a drawing period, and adjustable means to interrupt actuation of said operating means upon said arms reaching an upper position immediately below said stock piece whereby the horizontal position and alignment of said stock piece is maintained during the 10 disengagement of said stock piece from said die and carriage.

6. The combination of claim 5 further including means to re-initiate actuation of said operating means for effecting further upward movement of said arms to eject the stock piece from said apparatus.

7. A metal drawing apparatus having a bench, a support pivotally mounted on one side of said bench for pivotal movement about an axis extending generally parallel with said bench, an upwardly extending shaft journaled in said support, a discharge arm rigidly mounted at an end on the upper end of said shaft and adapted to extend horizontally across the bench when said support is in one position and to be tilted upwardly upon said support being rotated about said axis from said one position to a second position, said arm being adapted to swing downwardly upon rotation of said shaft from said upwardly tilted position to a generally horizontal retracted tilted position parallel with said bench, said shaft having a double-throw crank thereon of which the respective throws are substantially quadrantally related, power means engaging one throw of said crank to exert thereagainst a rectilinear force in one general direction with respect to said support, said crank and power means being so oriented with respect to the length of said arm that upon said arm being in upwardly tilted position said power means exerts a maximum of torque on said shaft in a direction tending to move said arm to said horizontally retracted tilted position while upon said arm reaching said latter position said torque diminishes to zero, and means engaging the other of said throws of said crank to exert thereagainst a yielding rectilinear force in the said general direction with respect to said support whereby said last mentioned means exerts a progressively increasing torque on said shaft opposing the diminishing torque exerted by said power means and the increasing torque exerted by the gravity of the arm upon said arm moving from said upwardly tilted position to horizontal retracted tilted position.

WALLACE E. KERR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,182,902 Nye et al Dec. 12, 1939 2,262,432 Rodder et al Nov. 11, 1941 2,369,467 Kerr Feb. 13, 1945 

